From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MlsND-0005Hv-Jc for qemu-devel@nongnu.org; Thu, 10 Sep 2009 18:44:15 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MlsN8-00058T-77 for qemu-devel@nongnu.org; Thu, 10 Sep 2009 18:44:14 -0400 Received: from [199.232.76.173] (port=60287 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MlsN8-00058F-1i for qemu-devel@nongnu.org; Thu, 10 Sep 2009 18:44:10 -0400 Received: from mx20.gnu.org ([199.232.41.8]:43477) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1MlsN7-0004db-JZ for qemu-devel@nongnu.org; Thu, 10 Sep 2009 18:44:09 -0400 Received: from verein.lst.de ([213.95.11.210]) by mx20.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1MlsN6-0004zy-TC for qemu-devel@nongnu.org; Thu, 10 Sep 2009 18:44:09 -0400 Date: Fri, 11 Sep 2009 00:44:01 +0200 From: Christoph Hellwig Subject: Re: [Qemu-devel] [PATCH v3 1/2] Add bdrv_aio_multiwrite Message-ID: <20090910224401.GB25700@lst.de> References: <1252511618-19497-1-git-send-email-kwolf@redhat.com> <1252511618-19497-2-git-send-email-kwolf@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1252511618-19497-2-git-send-email-kwolf@redhat.com> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: qemu-devel@nongnu.org One thing that concerns me here is that we keep adding more memory allocations to the I/O path. At least on fast SSDs even kernel memory allocations are a performance problem and they're much faster than userspace ones.